Tractors provided with front end loaders and any associated equipment controlled by hydraulics are generally provided with a valve arranged at the mounting structure of the front end loader or the base on the right side of the tractor, which connects the hydraulics of the tractor with the hydraulics of the front end loader and by means of which the operator controls the equipment. Conventional valves have two connection ports to the hydraulics of the tractor, one connection port to the pump of the tractor and one connection port to the tank of the tractor. Further, the valve normally has two pairs of motor port connections to the front end loader, of which one of the motor port connections in each pair is connected to one of the cylinder chambers of a pressure cylinder and the other motor port connection in the same pair is connected to the other cylinder chamber of the same pressure cylinder. A first such pressure cylinder may e.g. be arranged such that, when the first cylinder chamber of the pressure cylinder is filled with hydraulic fluid and the other is emptied to the tank, the front end loader is elevated, whereas the front end loader instead is lowered when the other cylinder chamber of the pressure cylinder is filled with hydraulic fluid and the other is emptied to the tank. The two motor port connections of the other pair may in the same example be connected to a pressure cylinder which controls a bucket on the front end loader such that it may be tipped up and down. Depending on whether the front end loader or the bucket is to be moved in the same direction as the load or in the opposite direction, the pump has to work more or less hard to achieve the necessary pressure for the operation.
For certain applications there is a need for yet further connections. A front end loader provided with a bucket may e.g. need to be completed with a gripping device to fasten and/or compress details in the bucket. In such a case, the tractor needs to be equipped with a valve which has three pairs of motor port connections to the front end loader. A problem is that valves are expensive, which means that it is expensive to exchange a functional valve provided with two pairs of motor port connections for a valve provided with three pairs of motor port connections.